Trivia: Originally Clair and Chris Redfield were to appear in the film after having been featured in previous movies. But script-changes lead to them being written out, and their fates were left ambiguous. Clair will be re-appearing in the sixth film, however.
Trivia: The footage of the T-cells Wesker injects Alice with is reused from Resident Evil: Afterlife, only in that one, it's the cure for the virus.
Chosen answer: They might bring them up in the next movie. Jill Vallentine was also lost for so many movies.
Anastasios Anastasatos